Pump



July 9, 1940- R. R.. BoYLEs ET A1.

PUMP

Filed July 13, 1938 6 Sheets-Sheet l /ITTOE'NEYS v QL lIIIIIIIII/VL/A/To'esv RALPH E. Bor/L55 EDWARD ,4. WIL HEL M OM V A a mal/425% EMS July 9, 1940. R. R. BoYLEs ETAL 2,207,575

' PUMP Filed July 13. 1938 6 Sheets-Sheet 2 .Z/-VVENTORS RALPH E. Bon E3EDWARD/l. W/LHE/ M @MM/iwf@ July 9, "1940.

Filed July i3, 1938 R. R. BOYLES Er A1.

PUMP

6 Sheets-Sheet 5 WW V 4 j N VEN TGRS EAL PH E'. Bo YL ES ED WARD/4.W/LHELM @yf-M "M ff'" if ATTozNEw/s i July 9, 1940. R. BOYLE s Er AL2,207,575

PUMP

Filed July 13, 1958 6 Sheets-Sheet 4 NVENTOES RALPH l'. Bo YL. E5 EDWARDAVV/L HELM M WMM July v9, 1940. a R. R. ,BoYLEs Er AL 2,207,575

' PUMP I Filed July 1s, 1938. e sheets-sheet s l 252 fwn/Toes ,B4/ PH E.Box/L E5 FIG ,6 EDWARD AVV/HELM Avro/cnrs July 9, 1940. RR. BoYLEs ETAL2,207,575

' PUMP l Filed July 13, 1938 6 Sheets-Sheet 6- F/GJ i,

VVENTOES RALPH E. BOY/ ES @Fmg @nu ZKM/L14 ATTORNEYS Patented July 9,1,940

UNITED STATES PATENT OFFICE PUMP Ralph R. Boyles and Edward A. Wilhelm,St. Paul, Minn., assignors to Waterous Company,` St. Paul, Minn., acorporation of Minnesota Application July 13, 1938, Serial No. 219,012

7 Claims.

o both series and parallel operation. At the same time the apparatusmust be physically adaptable to a wide variety of makes and models ofautomotive truck chassis and it must be compact and simple inconstruction for purposes of rst cost,

subsequent servicing, and ease of operation in the hands of relativelyinexperienced mechanics.

Itis an object of this invention to provide a pump structure having theaforesaid characteristics.

It is a further object of the invention to` provide a, pump of thecentrifugal type which may be mounted in a variety of positions on atruck chassis of standard construction.

It is a further object of the invention to provide a centrifugal pumpmechanism of the multistage type and a cooperating integrally formedtransfer valve mechanism by which the pump may be changed from aposition in which the pumping stages are operated in parallel with eachother to yield a high capacity at relatively low pressure to a positionin which the :pumping stagesare operated in s'eries relation to yield alower capacity at relatively high pressure.

the stages are operated in series relation and provided with additionalpassageways and means for the direct introduction of water when thestages are operated in parallelv relation.

It is also an object of the invention to provide a simpliied centrifugalpump construction of the multistage type having a housing whichiscomposed of only two main portions, and it is a further object of theinvention to providesuch a pump mechanism including transfer valve meansand passageways in only one of said main portions for the readyconversion of said mechanismirom a parallel to a series pumpingarrangement.

It is a further object of the invention to provide a, centrifugal pumpof the re engine type having widely spaced outlet delivery channels,together with a priming pump of the positive displacement type andautomatic valve mechanisms in said widely spaced channels for theautomatic priming of said centrifugal pump.

It is a further object of the invention to provide a series-parallelmultistage centrifugal pump composed generally of two housings andincluding an intake passage, one section of said pump passageways and atransfer valve arrangement in one of said housings, and an outletpassageway v and the other of said pump passageways in the other of saidhousings, which may be disassembled vmerely by separating said housingsections.

The specification is described with reference to the drawings, in whichA Figure 1 is a rear elevational view partly in section of the assembledpumping apparatus.

Figure 2 is a front elevational View partly in section of the assembledpumping apparatus.

Figure 3 is a'transverse cross-sectional view in the direction of thearrows 3-3 of Figure 1.

Figure 4. is a plan view partly in section of the upper haii only of thepump casing and discharge pipe connections, the section being at thelevel. of the line 4-4 of Figure 1.

Figure 5 is a plan view of the lower half only of the pump housing andinlet pipe connections showing the impellers, impeller shaft and bearinghousings in place on the housing.

Figure-6 'is a longitudinal cross-section of the pump and housing alongthe line 6--6 of Figure 5.

Figure 7 is a fragmentary longitudinal section of the volute of theiirst pump along the line 1-1 oi Figure 5,

Figure 8 is a fragmentary longitudinal section of the second volutealong the line 8--8 of Figure 5.

Figure 9 is a longitudinal sectional view in th direction of the arrows9-9 of Figure 3.

Figure 10 is a. plan View of the lower half of the pump housing andinlet pipe connection of a modification of the invention. f

Figure 11 is a plan view partly in section, of the upper half of thepump housing and outlet discharge pipe of the modified form of the pumpshown in Figure 10.

'Figure 12 is a longitudinal section through the volute of the firstpumping stage of the pump shown in Figures 10 and 11,'a1ong the linel2-I2 of Figure 11.

Figure 13 is a longitudinal section through the volute of the secondpumping stage, along the line iii-I3 of Figure 11.l

Figure 14 is a. longitudinal section through the center -dischargepassageway along the line |4-I4 of Figure 11.

Figure 15 is a fragmentaryview of a modified form of lower pump body foruse in the pump mechanism shown in Figures 1 through 9.

Figure 16 is a, fragmentary side elevation partly in section of themodified form of lower pump bod-y shown in Figure 15.

The pumping arrangement shown in Figures 1 through 9 inclusive consistsgenerally of a lower unit generally designated I0, which forms the lowerpump body and inlet water connection, and an upper unit generallydesignated 80, which forms the pump body and outlet water connection. i

The lower unit I0 of the pump is preferably a casting as shown inFigures 1, 2 and 5 and is formed with a transverse water inlet passage,generally designated I. By referring to the lefthand portion of Figure 5it will be seen that this passage begins at portion 2 and then isdivided by web |5 into branches I4 and I6. Branch I4 continuesunobstructedly to the inlet chamber of the first pumping stage, andthence to the right-hand end portion I3. -Branch |6 runs somewhatparallel to I4 but includes two valves.

At the right-hand end of passage I6, as shown in Figure 5, there ispositioned a check valve generally designated 20 which is shown incross-section in Figure 1. The valve 20 consists of a member 2| whichhas a through passage 22, and a valve face 23 upon which a valve ap 24operates. The flap 24 is pivoted in vthe member 2| and as shown inFigure 1, is oriented so as to prevent flow of water in the direction ofarrow 25. The entire valve body 2| is made cylindrical on its outersurface and is positioned in a cylindrical opening 26 in the lower pumpunit casting I0, as shown in Figure 5.l The opening 26 is covered andthe valve body-2| is heldin place by a cover plate 28 which is fastenedto the lower pump unit casting by a plurality of cap screws 29. Thecheck valve cage 20 being cylindrical may be rotated in its seat toclose passageway I3 in the event of failure of the `va1ve flap 24. Thusduring operation of the apparatus if valve ap 24 should fail, the entirecage 20 may be rotated 90 degrees and passageway I3 thus closed off.This closure does not preclude the operation of the pump since water mayenter the inlet portion 46 by way of channel i2 and passageway I6through valve 3|.

'A second cylindrical valve-receiving bore is provided in the lower pumpunit at 30 and receives a cylindrical transfer valve generallydesignated 3|. By referring to 'Figure 2 in which this valve is shown insection, it will be seen that this valve consists of a cage 32 which isformed integrally with a plate 33. The plate 33Vserves to close thelower end of the bore 30 in the housing,

and the cage 32, which is apertured, receives the rotatable element ofthe valve.

Within cage 32 there is pivotally mounteda valve-body 35 having aplurality of passageways 36 and 31 therethrough, as shown in Figure 5.The valve body isuprovided with a lower stub shaft 39 which is tted intoa bearing socket in the lower plate portion 33, and with an upwardlyextended. shaft 40 upon which an operating gear 4| is mounted. ,'Ifheshaft 40 protrudes through a portion 44 of the upper pump housingcasting which serves to close the upper opening of bore 30 in the lowerpump housing casting.

When the transfer valve generally designated 3| is in the position shownby the dotted lines of y Figure 5, the passageways I6 of the lower pumpvunit I0 communicate with passage 36 of the valve 3|, and through it,directly with the inlet chamber 46 of the second pump stage. valve bodyl35 is positioned with the passage 36, as shown in Figure 5, water mayflow from-passage I2 in the direction of arrow 49, through passageway 36and into chamber v46. Water may likewise flow in the direction of arrow50 from passage |3 through check valve 20 into the inlet chamber 46.

The passageway from |2^through I4 to chamvber 45 and from I3 through |4to chamber 45 is always open and water may therefore flow therethroughunrestrictedly either in the direction of arrow 5| or in the directionof arrow 52.-

The lower pump unit I0 is also provided with a passageway extending fromthe outlet of volute 66-61 of the first pump stage, which dischargesdownwardly into the lower housing as shown in Figure 7, to thepassageway 31 of transfer valve 3|, and thence, as shown in Figure 6,through another passageway 56 in the lower unit |0. Passageway 56extends from the transfer valve 3| under the pump shaft center bearing2|0 and upwardly through opening 58 (see Figures 4, 5

and 6) and then through discharge passageway 59 directly to thedischarge pipe |00 of the upper pump -unit 00.

The upper unit 80 of the pump body is provided with a portion 69 of thevolute of the second pumping stage, which is continuedA around at 10 inthe lower unit I0, and then through opening 1|, through passage 12 inthe lower pump body and into discharge pipe |00, all as shown in Figure8. The lower pump unit I0 and inlet pipe casting isA provided with aplurality of integrally formed bed plates 6| and 62 which are spacedapart so as to be adaptable to standard frame widths of automotivevehicles, as illustrated in Figure-1 wherein the frame of the automotivevehicle upon which the pump is mounted is shown in section at 63 and 64.y

As just' explained the upper pump body generally designated 80 comprisespassageways which cooperate with those in the lower pump body to formthe'volutes of the rst andsecond stages of Athe pump and with adischarge passageway |00 which is positioned so as to be directly aboveand generally parallel to the inlet passageway of the lower .pump bodyI0. 'Ihe upper pump body 80 is also provided with a portion 44 whichextends to the right, as shownv in Figure 2, so as .to overlie and forma cover for the cylindrical transfer valve opening 30 in the lower pumpbody |0. The upper and lower'pump bodies when bolted together by bolts 9form a unitary structure which'may be positioned with the inletandoutlet passageways arranged transversely on an automotive chassis. Y

The outer passageways l2 and |3 of the inlets of.the lower pump body |0are provided respec-I tively with inlet connections 15 and 16 which areVclosed at the ends with easily removable screw Thus when tion of arrows|01, the check valve element |06 is swungupwardly out of the path of theflow. However, when the pump is not in operation the check valveelements |06 fall downwardly under their own weight into contact withthe plate valve seat |04 and a vacuum may thus be drawn in the dischargepipe |00 and in the pump passageways for priming purposes, as will beexplained in greater detail hereinafter. 'I'he outer portion of member|05 is formed with a flange I 0 to which is bolted a cutoff valve I I Iwhich may be of any suitable construction. A valve is provided at eachdischarge end of pipe |00 so that the owfrom the pump may be directed inone or the other, or both directions, and the ow in either directionshut off at will by means of the valve.

By referring to Figure 3 it will be noted that the lower unit I0 of thepump body is provided with a web portion II5 at one side and with asecond web portion ||6 at the other. side of the pump. These websterminate in face plates II1 and I I8.- Web |I1 receives abearingstructure as shown at the left side' of Figure 3 and generallydesignated |20. Web 8 receivesgear housing, generally designated |50,and bearing structure generally designated |2| shown at theright side ofFigure 3.

The bearing structure generally shown at |20 comprises a barrel |22having a flange |23 throughout a portion of its circumference, as shownin Figure 2. The flange v|23 is attached to the face plate ||1 by aplurality of bolts |24. The barrel portion |22 is provided with ayballbearing |25, an end cap |26 and a greaseseal |21. The bearing |25 isthus enclosed in a grease-tight housing. The portion |28 of the barrelwhich extends toward the pump body is internally threaded to receive agland collar |30. Collar |30 is threaded at |3| and provided with a gearportion at |32. In web ||5 there is mounted a shaft |33 which carries aworm gear 34 which cooperates with the gear portion |32 of the gland nutand as the shaft |33 yis rotated gland |30 is likewise rotated, and dueto the threaded connection at |3|l theg.. ad is moved longitudinally onthe pump shaft. In this way it is possible to vary the pressure upon thepacking |35. At the opposite end of the pump shaft |40 there is provided,a somewhat similar housing'-` generally designated I2I which in thisinstance has an extended barrel portion I4| which passes through thegear housing |50. The barrel |4| supports two ball bearings |42 and |43on shaft |40. The barrel I4| is provided with a greaseretaining. ring|44 and with a Vgrease-tight cover plate |45 which is attached to thestructure by means of bolts |46, and is also provided with a 00 glandnut arranged similarly to that described above with reference to thbarrel |20, which' serves toA regulate the press e on packing |41.

' The gear housing generally designated |50, which is mounted betweenthe face plate I|8 of `the pump vstructure and theflange |48 of bearinghousing |2| is provided With a shaft |5| which is fitted for connectionin the drive shaft line of the automotive vehicle upon which the pumpingunit is mounted. The shaft |5| is, car-- ried by bearing |52 and by apilot bearing |53 which is carried in the end of a second shaft |54,

' also mounted in the housing on a pair .of ball bearings |55. The shaft|5| is provided with a. lsplined portion |56 lupon which thereisfslidably mounted a correspondingly. internally splined.;

. ferent diameters.

,shift gear |51 which is arranged to be moved from the position shown inFigure 3 to any of the dotted line positions |58, |59 or |60 by means ofa shift fork, a portion of which is indicated at |63. The shifting forkis arranged to be oper- `5 ated by a gear shift unit |64 shown in Figure1 as being mounted at one side of the gearing housing |50. Shafts I5Iand |54 are provided with suitable grease seals at |60 and |69respectively. 10

'I'he housing |50 is also provided with an idler gear |10 whichismounted by means of ball bearings |1I upon a fixed shaft |12. As shownin Figure 9, the gear |10 is of such a diameter that it meshes with agear |15 which is mounted l5 between bearings |42 and |43 upon the pumpshaft |40. 'Ihus when gear |51 is in the position shown by the fulllines in Figure 3 power from shaft |5I will be transmitted through gears|51 and |10 to gear |15, and the pump shaft |40 20 will accordingly berotated.

The housing |50 is also provided with another idler gear pair which iscomposed of an integrally formed unit of two gears of slightly dif- Thisgear pairis mounted be- 25 low and to one side of gear |51 as shown inFigures 2 and 9.l One of the gears of the pair meshes with slide gear|51 (when the latter is in position |58, Figure 3), and another of thegears of the pair meshes with a gear |8| (see Fig- 30 ures 2 and 9) onthe drive shaft of the priming pump, generally designated |85.

The priming pump consists of a casing |86 in which there is mounted apair of intermeshiug pump gears |81 and |88 whichv are fitted so as to35 rotate in contact with the interior of casing |86 as is well known ihthe art. The housing |86 is provided with an end plate |90 which isattached to the priming pump housing by means of screws |9I. 40

The priming pump |85 is provided with an inlet.. connection |94 whichcommunicates with the main pump outlet pipe |00 (see Figure 6) at flange|95 as shown in Figure 2.

The gear pair |80 is positioned in the housing 45 |50 so as tobe engagedby gear |51 when in the position |58, but to be out of engagement withgear |51 when the latter is moved to position |59. It will be noted thatin position |59 gear |51 is just out of contact with gear |98 which is50 carried by shaft |54. When gear |51 is in the position |60 gear |90fits neatly into the internal splines |99 of gear |51 so that power willbe transmitted from shaft |5| to |54.

VThe gearing arrangement in casing |50 thus 55 i has four operatingpositions. First, when the gear is in the position shown by the fulllines in Figure 3, power will, as previously explained, be transmittedfrom the shaft |5| to .'the main pump shaft |40. Second, when -the gear|51 60 is in the position |58, power will be transmitted from shaft |5|through gear pair |80 to the priming pump generally designated |85.Third, when thevgear I 51 is in the position |59, shaft |56 isdisconnected from both the priming pump 65 and the main pump andalsofrom the automotive drive shaft |54, or is in neutral. Fourth, whenthe gear |51 is in the position I 60 power will be transmitted fromshaft 5| to the drive shaft |54 of the automotive vehicle. 70

The main pump body, as previously explained, is divided into a lowercasting generally designated I0, and an upper casting generallydesignated 80. However, certain of the pump parts are integralthroughout their upper and lower 75 y ow of water thus portions. Thusthere are provided nosings 200 and 20| which surround the shaft |40 andare adapted to be carried by the split upper and lower housings.Similarly the wear rings 202, 204, 206 and 208 are integral throughouttheir circumference as is also the center bearing structure whichconsists of a center housing block 2|0 and insert 2| The block 2 i0 isprovided with passageways 2 I2 into which grease may be forced afterpumping water through a connection not shown. 'In assembling the pumpstructure the nosings 200 and 20| are fitted onto the shaft along withthe impellers 2|5 and 2|6, the center housing core 2|0,-2|| and rings202, 204, 206 and 208. The housing is then closed and the center housingcore rings and nosings are supported so that slight clearances aremaintained between the stationary nosings and the rotatable shaft |40and between the stationary rings 202, 204, 206 and 208 and the rotatable'impellers 2|5 and 2|6 adjacent them. This construction is desirable forsimplicity ofA manufacture, ruggedness and ease of assembly.

After the pump structure shown in Figures 1 through 9 has been mountedon an automotive vehicle and the necessary mechanical connection madebetween the drive shaft of the vehicle and the shaft |5|, the pump maybe placed inoperation as follows:

Either or bothof the caps 11 are removed and inlet hose connections aremade to a source oi' water, such as a fire hydrant, or to a reservoir.Outlet hoses are then connected to one or both of the valves During idleperiods the pump is always maintained dry so as vto preclude damage duefor instance to freezing conditions, and it is therefore necessary toprime the main pump. When water under pressure is available as atal firehydrant, water is forced `to the pump butwhen a reservoir or othersource is used the pump.

must be primed as follows: Gear shift mechanism |64 is manipulated,first to move the gear |51. out of engagement with gear |98 and intoengagement with the gear pair of the priming pump. The engine of vtheautomotive vehicle is then speeded up and the priming pump draws air outof the discharge pipe |00 of the main pump and through the communicatingpump passageways back to the intake. At this time' check valves |06 areboth closed as shown in Figure 2, and air is vthus prevented fromentering the main discharge pipe 00 from the hose line or lines whichmay be attached to the valves lli. The vacuum is thus drawn in the mainpump discharge and communicating passageways through the passageways tothe inlets |2| 3 through inlet connections 15-16 and to the supply hose,and water is accordingly elevated from the reservoir and the pump isfilled. The automotive engine is then idled and gear |51 is moved fromthe position |58 in which it was in operating connection with gear pair|80 to the position shown in Figure 3. During this time the water whichhas been drawn into the pump passageways and discharge pipe |00 ismaintained in place due to the action of check valves |03 which servedto hold the vacuum produced in the system by priming pump |05;`

After-the gear |51 has been shifted to the position shown in Figure 3the automotive engine is again accelerated and impellers 2|5 and 2|6 arethereafter effective to draw water through the inlet passageway |2V|3into the pump and discharge the water into the outlet passageway |00.The produced lifts the valve aps |06 and the water is discharged throughgate valves to the discharge hoses.

'For parallel operation the transfer valve is rotated by means ofhand-wheel 224 which operates through gears 220 and 4| (see Figures 1and 2) until the valve passageways 36 and 31 are in the positionsshownby the dotted lines of Figure 5. In this position passageway 36connects the passage |6 and inlet chamber 46 (see Figure- 5) andpassageg31 connects passage 55 with passage 56 (see Figures 5 and 6).The inlet supply is then by way of passageway I2 and water may flowdirectly along the path of arrow 5| to the inlet chamber 45 of the firstpump stage and may also ow in the direction of arrow 49 to the inletchamber. of the second pump stage. If the inlet supply should be throughpassageway I3 water may ow directly in the direction of arrow 52 tochamber 45 of thefflrst pump stage and through the check valve generallydesignated 20 and in the direction of arrow 50 to chamber 46 of thesecond pump stage.

Under these conditions the discharge from the volute 66-61 of the firstpumping stage is by way of passageway 55, passage 31 in the transfervalve 3|, thence through passage 56, as shownv in Figure 6, through 58,and v thence directly -through passage 59 to the discharge pipe |00 inthe upper pump body 80. At the same time discharge from the volute 69-10of the second stage (see Figures 5 and 8) is directly upward throughopening 1| and through passage 12 to the discharge pipe |00. Thus withthe transfer valve 3| in the position shown by the dotted lines inFigure 5 the `first and second pumping stages operate in parallel andthe-pump mechanism delivers a maximumof water ai; a predeterminedpressure.

For series operation the transfer valve 3l is again shifted by means ofhand-wheel '224 until passages 36 and 31 are moved to the positions`shown by the dot-dash lines of Figure 5. Passage 36 in the transfer'valve cylinder will then communicate from the discharge 55 of theflrst'pumping stage: to the inlet chamber 46 of the secondpumping-stage. At this time the short curved passage 31 of the transfervalve-is idle. The transfer valve in this latter position thus has theeffect first, of blocking the ow from the inlet |2 in the direction ofarrow 49 directly to the inlet chamber 46 of the second pumping stage,and second, of interrupting the flow from the discharge passage 55through the passage 56 of the lower pump body through opening 58 andpassage 50 (Figures 10 and 1-1) to the main discharge pipe |00.Underthese conditions series operation of the pump ensues as follows:

Water is drawn into the chamber,45 of the first pumping stage either. inthe direction of arrow 5| from inlet passage |2 or infthe direction ofarrow 52 from inlet passage I3, depending upon to which side of themachine the inlet hose is connected. The .ow then proceedsthroughchamber 45 through the impeller 2|6 to the volute. 66--'61 (seeFigure 7) of the first stage,-thence through passageway 55 in the lowerpump body through transfer valve passage' 36 (which'is in the positionshown by the dot-dash lines of Figure 5) and thence tothe inlet chamber46 of the second pumping stage. From this point the water is deliveredby impeller 2|5 to the volute 69-10 (see Figure 8) of the secondvpumping stage through opening and passage 12 to the main outlet pipe|00. Under these conditions the ,pumping apparatus delivers a maximumpressure with a comparatively smaller ow. At this time also it lwill benoted that pressure is de- 7| a d thence directly upwardlyh() veloped inpassageway I6 between the transfer valve and the suction check valve 20(see Figure 5), and as a result the gate 24 of the check valve 20 isforced shut against the valve face 23 .with the result that back flowinto the inlet passage I3 from the inlet of the second stage isprevented.

Whenever desired, the transfer valve 3| may be changed from the positionin whichthe pumping stages operate in parallel to the position in whichthey operate in series, merely by rotating gear 4| (see Figure 2) bymeans of Worm gear 220 which is mounted upon shaft 22| (see Figure 1).The shaft 22| is pivotally mounted in upstanding lugs 222, formed as anintegral portion of the upper pump body 80. Shaft 22| is also providedwith an extended portion 223 and a hand wheel 224 so that it may beoperated conveniently from one side of the automotive vehicle.

In the device shown in Figures 1 through 9 Water from inlet port I3 mayreach the inlet chamber 46 of the second pumping stage through lthecheck valve generally designated 20 and passage |6, and to a limitedextent flow may-occur from I3 along arrow 52 to and through the inletchamber of the first pump stage then through I4 oppositely to arrow 5|around the end of web I5 then in the direction of arrow 49 through I6and 36 again to the inlet chamber 4.6. However this flow is negligibledue to the shaping, the passageways and the tortuousness of the path. Inthe modification shown in Figures 11 through 13 this path has been easedby adequately sizing the passage I4 to accommodate the flow to both pumpstages and-by omitting sharp bends. As a consequence flow to the secondpumping stage is provided only through the transfer valve 3| and thebranch I6 and check valve 20 of therst modication (see Figure 5) areaccordingly omitted.

portion of the flow may continue in the direc- .f

tion of arrow through passageway 36 of the transfer valve 3|, to theinlet chamber 46 of the second pumping stage. It will be recalled thatin the first modification the flow 50 was directly from the inlet-passage |3 through the check valve 20 to the inlet chamber 46 but inthe second modification the inlet flow to the chamber 46 is first takentransversely of the pump and' thence around through the transfer valvet0 the inlet chamber 46. This modification of the invention is otherwisesimilar tothe first modification, shown in Figures 1 through 9, except`lfor slightly different' shaping of passageway |00, as shown in Figure11 and of the transfer passage 56 from the vtransfer valve 3| throughopen` ing 50 and passage 59 to the discharge pipe |00, as will b'e seenby comparing Figure, 14 and Fig- `ure 6. In Figure 14 the center bearingportion lis of reduced diameter' as compared with that' shown in Figure6. l

In both of the modifications the transfer passage 56 and the transfervalve 3| are located in the lower half of the vpump body. By thuslocating those elements of `the mechanism we have been ableto achieve amuch smaller overall height of the pump mechanism and a. much morecompact and easily accessible pump than in previous mechanisms of thistype.

In Figures 15 and 16 there is illustrated a modified form of lower unitfor use in the pump shown in Figures 1 through 9. In this modificationthe web 250 which divides passages I4 and I6 is extended out to theflange end of inlet I3 and the check valve is likewise moved out to thenew position as shown at 25|. The inlet gooseneck pipe 252 is providedwith a web 253 which terminates in a valve seat portion 254 againstwhich valve 25| seats. The valve 25| is pivoted upon pintle 255 which isin turn supported from the gooseneck inlet casting 252.

It is obvious that many modifications may be made without departing fromthe spirit of the invention herein described and claimed as follows:

We claim:

1. A two-stage centrifugal pump comprising a rotary member having firstand second stage impellers in spaced relation thereon, an axiallydivided housing having upper and lower sections,

said housing being formed with an inlet to each impeller in said lowersection, andwith first and second volutes part in each section for thefirst and second impellers respectively, including an outlet passagewayin the upper section communicating directly with the second volute, adischarge connection from the first volute to said outlet passageway,said discharge connection being located between the volutes in saidlower section, a second inlet to the second impeller, said inlet alsobeing in the lower section, and valve means in said lower section fortransferring the fiow from the first volute into the dischargeconnection or into said second inlet connection.

2. A two-stage centrifugal pump comprising a rotary member having afirst and second impeller in spaced relation thereon, a housing for saidrotary member and impellers, said housing being divided axially intoupper .and lower sections and including intakes and spaced first and.

second volutes for said spaced first and second impellers, respectively,a discharge passage for parallel operation of said impellers, saidpassage being in the lower housing section between the spaced volutesand beneath said rotary member, an outlet pipe formed on said upperhous- 3. A multiple stage centrifugal pump system 'l adapted formounting upon an automotive chassis for fire engine service, comprisingan open-ended water inlet manifold, an open-ended water outlet manifoldof a length substantially corresponding to that of the inlet manifoldarranged substantially parallel with and above the outlet manifold, apump shaft having primaryand secondary imlpellersin spaced relationthereon mounted between said manifplds and in a plane which issubstantially at right angles to the manifolds, a pump housing includingan intake and discharge volutefor each impeller arranged between saidmanifolds, said housing being divided into upper and lower portionsalong a. plane passing through the .said pump shaft, the lower housingbeing u the discharge volute of the first impeller to the second branchpassageway and a transfer valve located in the lower housing for closingthe second branch passage from" the intake manifold to the secondaryimpeller and for directing the flow` from the discharge volute of saidprimary impeller to the branch passage of the secondary impeller.

4. A multiple stage centrifugal pump system adapted for mounting upon anautomotive chassis for nre engine service, comprising an open-ended,water inlet manifold, an open-ended water outlet manifold of a lengthcorresponding to that of the inlet manifoldl arranged substantiallyparallel with and above the outlet manifold, a pump shaft having firstand second impellers in spaced relation thereon mounted between saidmanifolds and in a plane which is substantially at right angles to themanifolds, a pump housing including an intake and a discharge volute foreach impeller arranged between said manifolds, said housing beingdivided into upper and lower portions along a plane passing through thesaid pump shaft, the lower housing being formed with a direct passagewaybetween the intake'manifold and the intake of one of the rst impellerand with a discharge'passage from that impeller to said outlet manifold,saidlower housing also being formed with a branch passageway from theintake manifold to the intake of the second impeller, and a manuallycontrolled valve in said lower housing for simultaneously controlling owsageway to the second impeller and interrupting' the flow from theintake manifold .through said branch passagewayto the 'second impeller.

5. vA two-stage centrifugal pump system adapted for mounting upon anautomotive chassis vfor -fire engine service comprising an open-endedwater inlet manifold and support, an open-ended' water outlet manifoldof a length corresponding to said inlet manifold length and arranged`sub stantially parallel with and above the outlet manifold', a'pumprotor having first and second impellers thereon arranged between themanifolds and at an angle thereto, a housing includand passageway meansand tran ing an inlet for the impellers and with downwardly and upwardlydischarging volutesfor the first and second impellers respectively, saidhousing being divided into upper an lower sections, r valve means insaid lower section for in one condition directing ow from the downwardlydischarging volute of the first' impeller to the' outlet manifold andfor directing uid inflow from fthe inletmanifold to the inlet of thesecond impeller, and in another' condition for interrupting such inflowand for transferring the ow from thev rst impellervolute to the intakeof the second impeller.

6. A multiple stage centrifugal pump system adapted for mounting upon anautomotive chassis for re engine service, comprising an open-ended waterinlet manifold, an open-ended water outlet manifoldof a lengthsubstantially corresponding to that of the inlet manifold arrangedsubstantially parallel with and above the outlet manifold, a pump shafthaving ,primary and secondary impellers in spaced relation thereonmounted between said manifolds and in a plane which is substantially atrightangles to the manifolds, a pump housing including an intake anddischarge volute for each impeller arranged between said manifolds, saidhousing being divided into upper and lower portions along a planepassing through the said pump shaft, the lower housing being formed witha direct passageway between the intake manifold and the intake of theprimary impeller, a Abranch passageway from the intake manifold to theintake of the secondary impeller, said lower housing also being formedwith a transfer passage from the discharge volute of the first impellerto the branch passageway and a transfer valve located in the lowerhousing for closing the branch passage from the intake manifold to thesecondary impeller and for directing the flow from the discharge voluteof the vsaid primary impeller to said branch passage of the secondaryimpeller.

7. A multiple stage centrifugal pump system adapted for mounting upon anautomotive chassis for re engineservice, comprising an open-ended waterinlet manifold, an open-ended water outlet manifold of a lengthsubstantially corresponding to that of the inlet manifold arrangedsubstan-L tially parallel with and above the outlet manifold, apumpshaft having primary and secondary impellers in spaced relation thereonmounted be, tween said manifolds and in a plane which is substantiallyat right angles to the manifolds, a pump housing including an intake anddischarge volute" for each impeller arranged between said manifolds,said housing being divided into upper` and lower portions along a planepassing through the said pump shaft, the lower housing being formed witha direct passageway between the intake manifold and the intake of theprimary impeller and with first and second branch passageways from theintake manifold tothe intake of the secondary impeller, a check valve inthe, rst said branch passageway, said llower housing also being formedwith a transferI passage from the discharge volute of the lfirstimpeller to the second branch passageway and atransfer vvalve located inthe lower housing for closing the second branch passageway from theintake manifold and the secondary impeller and for directing the iiowfrom the discharge volute of said primary impeller to the branch passageof the secondary impeller, said checkvalve being carried by acylindrical valve cage positioned transversely of said first branchpassageway, said cage being/rotatable to close off said passageway inthe eventbf failure of the check valve.

